1. Field of the Invention
The present invention relates to a percolator unit with a movable infusion chamber which is detachable without using tools.
2. Discussion of Background Information
The percolator unit is adapted to make, under fully automatic conditions and without human intervention, a hot beverage, such as coffee of the expresso type, that is delivered and dispensed to the consumer immediately after being percolated.
The devices currently available are most often based on the use of a vertical cylinder constituting the infusion chamber in which a certain quantity of ground coffee is poured which is retained by a grid constituting the bottom of said cylinder. A piston that is displaced vertically first compresses the coffee powder, through which hot water is then injected and evacuated afterward.
The presence of the movable piston above the cylinder makes the operation of pouring the coffee powder difficult, imparting a complicated flow and requiring movable guiding means.
European Patent No. EP 0 521 861, filed by the same inventor, overcomes these drawbacks partially. The EP document describes a device equipped with a mechanical unit positioned horizontally in which the movements of the movable elements are all caused by two racks having inverted horizontal displacements driving a series of tie bars sliding on supports, the infusion chamber having a horizontal axis, in which the flow of hot water occurs vertically, being extended by a horizontal movable filling chamber in which the coffee powder is directly poured.
European Patent No. EP 0 634 904, also filed by the Applicant, describes a percolator constituted of a movable horizontal mechanical assembly equipped with an infusion chamber having a movable bottom extended by a filling chamber that is displaced simultaneously with the movable bottom, the main members of the assembly being made from functional sections, particularly a stationary rail, the infusion chamber as well as a movable part sliding on the stationary rail and carrying the compression piston, as well as a main rack driving a secondary rack by means of a stationary pinion, the filling chamber and the movable bottom also sliding on this stationary rail.
These devices are relatively complex given the presence of a filling chamber and the driving of the movable parts by several racks while remaining detachable.
The object of the device according to the instant invention is to overcome these drawbacks. Indeed, the invention allows obtaining an automatic machine for percolating under pressure comprising a small number of parts that are highly reliable and relatively easy to maintain, and especially having the advantage of being able to use two coffee grinders, therefore for two different coffees, regular and decaffeinated, for example, or two types of different coffees.
The invention comprises a horizontally arranged mechanical unit comprising three elements:
a stationary part including a base, the powering component, the driving component and the injection piston,
a removable slide bearing the coffee flow conduit and, additionally,
a movable part including an infusion chamber, a counter-plunger and an articulated scraper whose movements are actuated by the displacements of the infusion chamber generated by two tie rods actuated by a screw driven by a gear motor.
According to the invention, a percolator comprises a movable infusion chamber adapted to make, under fully automatic conditions, a hot beverage through cycle phases including filling, compression, infusion, extraction and sweeping of the grounds. A mechanical unit is arranged horizontally in the percolator, the mechanical unit comprising a fixed part including a base provided with two primary rails, a powering component, a driving component and an injection piston, and a movable part including an infusion chamber, a counter-plunger and an articulated scraper assembly. The movements of the counter-plunger and of the scraper assembly is actuated by the displacements of the infusion chamber resulting from sliding of two tie-rods in borings provided in a vertical piston bearing plate that is affixed to the base. One end of each tie-rod is secured to a movable plate being displaced on the primary rails and actuated by a driving system adapted to move the infusion chamber in both directions along two horizontal secondary rails affixed to a movable slide bearing a front plate and a hot beverage flow conduit, the secondary rails sliding in the two primary rails of the base.
According to another aspect of the invention, the movable infusion chamber may be detachable without using tools. The driving system may comprise a screw that is parallel to the axis of the infusion chamber, driven by a gear motor and rotating in a nut affixed to the movable plate. The driving of the screw by the gear motor may occur by way of a rapid coupling, the driving nut mounted on the movable plate comprising a pressure box, the stopping and reversing of the movement being controlled directly by an electronic torque sensor controlling the pressure so as to eliminate micro-switches normally used.
According to yet another aspect of the invention, the driving system may comprise a double action cylinder actuated by way of pressurized water originating from the pump that also furnishes the water adapted for infusing the hot beverage. Controlling the position of the cylinder, as well as the quantity of water to be infused, may occur due to a single flow meter associated with a programmable system actuating electrovalves. The counter-plunger may be driven by an annular shoulder arranged at the bottom of the infusion chamber and acting on one of the head and two abutments affixed to the counter-plunger. The counter-plunger may comprise two flexible tongues butting against an annular boss affixed to the flow conduit so as to restrict its movement at the beginning of the extraction phase. The hot beverage may comprise coffee. The coffee grounds may be placed in the percolator, wherein for the infusion phase, hot water enters through the stationary piston and traverses the coffee grounds, and wherein the beverage thus obtained leaves through an orifice of the counter-plunger extended rearwardly by a tube sliding in the flow conduit to leave the percolator.
Moreover, according to the invention, the scraper assembly may be borne by a lateral arm rotating about a horizontal pivot perpendicular to the longitudinal axis of the percolator and mounted on a movable part sliding on the secondary rails and maintained in a resting position by a spring and an abutment, the arm comprising a device provided to tilt the arm downwardly by butting against the front plate, one of a return abutment and rack forcing the device to resume its original position during the return.
According to the invention, the front surface of the counter-plunger may be cambered along the path followed by the scraper assembly during removal of the coffee grounds, so as to improve the efficiency of the sweeping. The infusion chamber, the counter-plunger and the movable part of the scraper assembly are driven by the tie-rods due to one of ribs or fins thereof located on the sides of the infusion chamber, the tie rods being pivotable one quarter turn so as to allow one of locking and release of the assembly. The bodies of the infusion chamber and of the movable part of the scraper assembly may include passages whose form allows them to slide on the one of ribs or fins when the tie rods are in the unlocked position. The scraper assembly may comprise a cam.
According to another aspect of the invention, the front plate may comprise holes allowing the passage of the tie rods, regardless of their position. After the sweeping phase, the tie rods may extend beyond the front of the front plate to allow the user to pivot them one quarter turn due to the one of ribs or fins to obtain the unlocking in order to extract the assembly for cleaning and maintenance. The infusion chamber may comprise, for each tie rod, double supports bearing the passages and arranged on each side of one of the ribs and fins such that the infusion chamber is driven in both directions by the movements of the tie rods. The filling the infusion chamber may be done from the top due to an upper opening.
According to yet another aspect of the invention, filling the infusion chamber may be done on the sides, through lateral openings allowing use of two grinders that are individually controllable and to output on request two distinct hot beverages.